Monitoring food and health news -- with particular attention to fads, fallacies and the "obesity" war

Summary of findings to date: Everything you can possibly eat or drink is both bad and good for you

"Let me have men about me that are fat... Yond Cassius has a lean and hungry look ... such men are dangerous." -- Shakespeare

Sunday, October 14, 2012

Caffeine protects against Alzheimer's

In oxygen-deprived mice

Recent studies have linked caffeine consumption to a reduced risk of Alzheimer's disease, and a new University of Illinois study may be able to explain how this happens.

"We have discovered a novel signal that activates the brain-based inflammation associated with neurodegenerative diseases, and caffeine appears to block its activity. This discovery may eventually lead to drugs that could reverse or inhibit mild cognitive impairment," said Gregory Freund, a professor in the U of I's College of Medicine and a member of the U of I's Division of Nutritional Sciences.

Freund's team examined the effects of caffeine on memory formation in two groups of mice—one group given caffeine, the other receiving none. The two groups were then exposed to hypoxia, simulating what happens in the brain during an interruption of breathing or blood flow, and then allowed to recover.

The caffeine-treated mice recovered their ability to form a new memory 33 percent faster than the non-caffeine-treated mice. In fact, caffeine had the same anti-inflammatory effect as blocking IL-1 signaling. IL-1 is a critical player in the inflammation associated with many neurodegenerative diseases, he said. "It's not surprising that the insult to the brain that the mice experienced would cause learning memory to be impaired. But how does that occur?" he wondered.

The scientists noted that the hypoxic episode triggered the release of adenosine by brain cells. "Your cells are little powerhouses, and they run on a fuel called ATP that's made up of molecules of adenosine. When there's damage to a cell, adenosine is released," he said. Just as gasoline leaking out of a tank poses a danger to everything around it, adenosine leaking out of a cell poses a danger to its environment, he noted.

The extracellular adenosine activates the enzyme caspase-1, which triggers production of the cytokine IL-1β, a critical player in inflammation, he said. "But caffeine blocks all the activity of adenosine and inhibits caspase-1 and the inflammation that comes with it, limiting damage to the brain and protecting it from further injury," he added.

Caffeine's ability to block adenosine receptors has been linked to cognitive improvement in certain neurodegenerative diseases and as a protectant against Alzheimer's disease, he said.

"We feel that our foot is in the door now, and this research may lead to a way to reverse early cognitive impairment in the brain. We already have drugs that target certain adenosine receptors. Our work now is to determine which receptor is the most important and use a specific antagonist to that receptor," he said.

After hypoxia, a critical adverse outcome is the inability to create new memories. How anterograde amnesia develops or resolves remains elusive, but a link to brain-based IL-1 is suggested due to the vital role of IL-1 in both learning and brain injury. We examined memory formation in mice exposed to acute hypoxia. After reoxygenation, memory recall recovered faster than memory formation, impacting novel object recognition and cued fear conditioning but not spatially cued Y-maze performance. The ability of mice to form new memories after hypoxia/reoxygenation was accelerated in IL-1 receptor 1 knockout (IL-1R1 KO) mice, in mice receiving IL-1 receptor antagonist (IL-1RA), and in mice given the caspase 1 inhibitor Ac-YVAD-CMK. Mechanistically, hypoxia/reoxygenation more than doubled caspase 1 activity in the brain, which was localized to the amygdala compared to the hippocampus. This reoxygenation-dependent activation of caspase 1 was prevented by broad-spectrum adenosine receptor (AR) antagonism with caffeine and by targeted A1/A2A AR antagonism with 8-cyclopentyl-1,3-dipropylxanthine plus 3,7-dimethyl-1-propargylxanthine. Additionally, perfusion of adenosine activated caspase 1 in the brain, while caffeine blocked this action by adenosine. Finally, resolution of anterograde amnesia was improved by both caffeine and by targeted A1/A2A AR antagonism. These findings indicate that amygdala-based anterograde amnesia after hypoxia/reoxygenation is sustained by IL-1β generated through adenosine-dependent activation of caspase 1 after reoxygenation.

Goodie! I have been having bacon 'n eggs for breakfast most mornings for many years. Now I can rest easy

Bacon has been long considered unhealthy due to the use of nitrates and nitrites in the curing process. Many conventional doctors, and well-meaning friends and relatives, will say you’re basically asking for a heart attack or cancer by eating the food many Paleo enthusiasts lovingly refer to as “meat candy”.

The belief that nitrates and nitrates cause serious health problems has been entrenched in popular consciousness and media. Watch this video clip to see Steven Colbert explain how the coming bacon shortage will prolong our lives thanks to reduced nitrates in our diets.

In fact, the study that originally connected nitrates with cancer risk and caused the scare in the first place has since been discredited after being subjected to a peer review. There have been major reviews of the scientific literature that found no link between nitrates or nitrites and human cancers, or even evidence to suggest that they may be carcinogenic. Further, recent research suggests that nitrates and nitrites may not only be harmless, they may be beneficial, especially for immunity and heart health. Confused yet? Let’s explore this issue further.

It may surprise you to learn that the vast majority of nitrate/nitrite exposure comes not from food, but from endogenous sources within the body. (1) In fact, nitrites are produced by your own body in greater amounts than can be obtained from food, and salivary nitrite accounts for 70-90% of our total nitrite exposure. In other words, your spit contains far more nitrites than anything you could ever eat.

When it comes to food, vegetables are the primary source of nitrites. On average, about 93% of nitrites we get from food come from vegetables. It may shock you to learn that one serving of arugula, two servings of butter lettuce, and four servings of celery or beets all have more nitrite than 467 hot dogs. (2) And your own saliva has more nitrites than all of them! So before you eliminate cured meats from your diet, you might want to address your celery intake. And try not to swallow so frequently.

All humor aside, there’s no reason to fear nitrites in your food, or saliva. Recent evidence suggests that nitrites are beneficial for immune and cardiovascular function; they are being studied as a potential treatment for hypertension, heart attacks, sickle cell and circulatory disorders. Even if nitrites were harmful, cured meats are not a significant source, as the USDA only allows 120 parts per million in hot dogs and bacon. Also, during the curing process, most of the nitrite forms nitric oxide, which binds to iron and gives hot dogs and bacon their characteristic pink color. Afterwards, the amount of nitrite left is only about 10 parts per million.

And if you think you can avoid nitrates and nitrites by eating so-called “nitrite- and nitrate-free” hot dogs and bacon, don’t be fooled. These products use “natural” sources of the same chemical like celery and beet juice and sea salt, and are no more free from nitrates and nitrites than standard cured meats. In fact, they may even contain more nitrates and nitrites when cured using “natural” preservatives.

It’s important to understand that neither nitrate nor nitrite accumulate in body. Ingested nitrate from food is converted into nitrite when it contacts our saliva, and of the nitrate we eat, 25% is converted into salivary nitrite, 20% converted into nitrite, and the rest is excreted in the urine within 5 hours of ingestion. (3) Any nitrate that is absorbed has a very short half-life, disappearing from our blood in under five minutes. (4) Some nitrite in our stomach reacts with gastric contents, forming nitric oxide which may have many beneficial effects. (5, 6) You can listen to my podcast “Does Red Meat Increase Your Risk of Death?“ for more information on this topic.

In general, the bulk of the science suggests that nitrates and nitrites are not problematic and may even be beneficial to health. Critical reviews of the original evidence suggesting that nitrates/nitrites are carcinogenic reveals that in the absence of co-administration of a carcinogenic nitrosamine precursor, there is no evidence for carcinogenesis. (7) Newly published prospective studies show no association between estimated intake of nitrite and nitrite in the diet and stomach cancer. (8) Nitric oxide, formed by nitrite, has been shown to have vasodilator properties and may modulate platelet function in the human body, improving blood pressure and reducing heart attack risk. (9, 10, 11) Nitrates may also help boost the immune system and protect against pathogenic bacteria (12, 13, 14)

So what do we take from this? There’s no reason to fear nitrates and nitrites in food. No reason to buy nitrate-free, uncured bacon. No reason to avoid cured meats in general, particularly those from high quality sources. In fact, because of concerns about trichinosis from pork, it makes a lot more sense in my opinion to buy cured bacon and other pork products. I do.

Where it is not bunk is when it shows that some treatment or influence has no effect on lifespan or disease incidence. It is as convincing as disproof as it is unconvincing as proof. Think about it. As Einstein said: No amount of experimentation can ever prove me right; a single experiment can prove me wrong.

Epidemiological studies are useful for hypothesis-generating or for hypothesis-testing of theories already examined in experimental work but they do not enable causative inferences by themselves

The standard of reasoning that one commonly finds in epidemiological journal articles is akin to the following false syllogism:
Chairs have legs
You have legs
So therefore you are a chair

I am rather in despair that important medical research is plagued by arrant nonsense. The simple truth that correlation is not causation seems unknown to most medical writers. As a last ditch attempt to get that truth into a few more skulls let me be "offensive". Offensiveness may serve to get the matter noticed. So here is the story: There is about a -.5 correlation between lip size and IQ. Big lips predict low IQ. Your run-of-the mill medical researcher will pounce on that as a huge breakthrough in finding the causes of IQ -- and propound new theories about things such as blood circulation to explain how lips affect IQ. But that is nonsense. Big lips are mostly found on people of African ancestry and, as all the studies attest, Africans are a very low IQ group. The correlation arises because of heredity, not lip size. There is a third factor behind the correlation -- and the possibility of such third factors seems to be a jaw-dropping surprise to most medical researchers

SALT -- SALT -- SALT

1). A good example of an epidemiological disproof concerns the dreaded salt (NaCl). We are constantly told that we eat too much salt for good health and must cut back our consumption of it. Yet there is one nation that consumes huge amounts of salt. So do they all die young there? Quite the reverse: Japan has the world's highest concentration of centenarians. Taste Japan's favourite sauce -- soy sauce -- if you want to understand Japanese salt consumption. It's almost solid salt.

2). We need a daily salt intake to counter salt-loss through perspiration and the research shows that people on salt-restricted diets die SOONER. So the conventional wisdom is not only wrong. It is positively harmful

3). Table salt is a major source of iodine, which is why salt is normally "iodized" by official decree. Cutting back salt consumption runs the risk of iodine deficiency, with its huge adverse health impacts -- goiter, mental retardation etc. GIVE YOUR BABY PLENTY OF SALTY FOODS -- unless you want to turn it into a cretin

4). Our blood has roughly the same concentration of salt as sea-water so claims that the body cannot handle high levels of salt were always absurd

5). The latest academic study shows that LOW salt in your blood is most likely to lead to heart attacks. See JAMA. 2011;305(17):1777-1785. More here and here and here for similar findings. Salt is harmless but a deficiency of it is not. We need it. See also here

PEANUTS: There is a vaccination against peanut allergy -- peanuts themselves. Give peanut products (e.g. peanut butter -- or the original "Bamba" if you have Israeli contacts) to your baby as soon as it begins to take solid foods and that should immunize it for life. See here and here (scroll down). It's also likely that a mother who eats peanuts while she is lactating may confer some protection on her baby. See here

THE SIDE-EFFECT MANIA. If a drug is shown to have troublesome side-effects, there are always calls for it to be banned or not authorized for use in the first place. But that is insane. ALL drugs have side effects. Even aspirin causes stomach bleeding, for instance -- and paracetamol (acetaminophen) can wreck your liver. If a drug has no side effects, it will have no main effects either. If you want a side-effect-free drug, take a homeopathic remedy. They're just water.

Although I am an atheist, I have never wavered from my view that the New Testament is the best guide to living and I still enjoy reading it. Here is what the apostle Paul says about vegetarians: "For one believeth that he may eat all things: another, who is weak, eateth herbs. Let not him that eateth despise him that eateth not; and let not him which eateth not judge him that eateth." (Romans 14: 2.3). What perfect advice! That is real tolerance: Very different from the dogmatism of the food freaks. Interesting that vegetarianism is such an old compulsion, though.

Even if we concede that getting fat shortens your life, what right has anybody got to question someone's decision to accept that tradeoff for themselves? Such a decision could be just one version of the old idea that it is best to have a short life but a merry one. Even the Bible is supportive of that thinking. See Ecclesiastes 8:15 and Isaiah 22: 13. To deny the right to make such a personal decision is plainly Fascistic.

Obesity does NOT causes diabetes. But insatiable eating is a prominent symptom of diabetes. So diabetes DOES cause obesity, which accounts for the correlation between the two things. The streets are full of fatties who don't have diabetes. How come? If conventional medical theory were correct we should be in the midst of an epidemic of diabetes. A recent high quality study has also found that fatties are LESS likely to die of diabetes

Elite people frequently express disapproval of red meat eating as a way of expressing their felt superiority to the ordinary people who eat it

IQ: Political correctness makes IQ generally unmentionable so it is rarely controlled for in epidemiological studies. This is extremely regrettable as it tends to vitiate findings that do not control for it. When it is examined, it is routinely found to have pervasive effects. We read, for instance, that "The mother's IQ was more highly predictive of breastfeeding status than were her race, education, age, poverty status, smoking, the home environment, or the child's birth weight or birth order". So political correctness can render otherwise interesting findings moot

"To kill an error is as good a service as, and sometimes better than, the establishing of a new truth or fact" -- Charles Darwin

"Most men die of their remedies, not of their diseases", said Moliere. That may no longer be true in general but there is still a lot of false medical "wisdom" around that does harm to various degrees -- the statin and antioxidant fads, for instance. And showing its falsity is rarely the problem. The problem is getting people -- medical researchers in particular -- to abandon their preconceptions

Bertrand Russell could have been talking about today's conventional dietary "wisdom" when he said: "The fact that an opinion has been widely held is no evidence whatever that it is not utterly absurd; indeed in view of the silliness of the majority of mankind, a widespread belief is more likely to be foolish than sensible.”

The challenge, as John Maynard Keynes knew, "lies not so much in developing new ideas as in escaping from old ones".

"Obesity" is 77% genetic. So trying to make fatties slim is punishing them for the way they were born. That sort of thing is furiously condemned in relation to homosexuals so why is it OK for fatties?

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Some more problems with the "Obesity" war:

1). It tries to impose behavior change on everybody -- when most of those targeted are not obese and hence have no reason to change their behaviour. It is a form of punishing the innocent and the guilty alike. (It is also typical of Leftist thinking: Scorning the individual and capable of dealing with large groups only).

2). The longevity research all leads to the conclusion that it is people of MIDDLING weight who live longest -- not slim people. So the "epidemic" of obesity is in fact largely an "epidemic" of living longer.

3). It is total calorie intake that makes you fat -- not where you get your calories. Policies that attack only the source of the calories (e.g. "junk food") without addressing total calorie intake are hence pissing into the wind. People involuntarily deprived of their preferred calorie intake from one source are highly likely to seek and find their calories elsewhere.

4). So-called junk food is perfectly nutritious. A big Mac meal comprises meat, bread, salad and potatoes -- which is a mainstream Western diet. If that is bad then we are all in big trouble.

5). Food warriors demonize dietary fat. But Eskimos living on their traditional diet eat huge amounts of fat with no apparent ill-effects. At any given age they in fact have an exceptionally LOW incidence of cardiovascular disease. And the average home-cooked roast dinner has LOTS of fat. Will we ban roast dinners?

6). The foods restricted are often no more calorific than those permitted -- such as milk and fruit-juice drinks.

7). Tendency to weight is mostly genetic and is therefore not readily susceptible to voluntary behaviour change.

8). And when are we going to ban cheese? Cheese is a concentrated calorie bomb and has lots of that wicked animal fat in it too. Wouldn't we all be better off without it? And what about butter and margarine? They are just about pure fat. Surely they should be treated as contraband in kids' lunchboxes! [/sarcasm].

9). And how odd it is that we never hear of the huge American study which showed that women who eat lots of veggies have an INCREASED risk of stomach cancer? So the official recommendation to eat five lots of veggies every day might just be creating lots of cancer for the future! It's as plausible (i.e. not very) as all the other dietary "wisdom" we read about fat etc.

10). And will "this generation of Western children be the first in history to lead shorter lives than their parents did"? This is another anti-fat scare that emanates from a much-cited editorial in a prominent medical journal that said so. Yet this editorial offered no statistical basis for its opinion -- an opinion that flies directly in the face of the available evidence.

11). A major cause of increasing obesity is certainly the campaign against it -- as dieting usually makes people FATTER. If there were any sincerity to the obesity warriors, they would ban all diet advertising and otherwise shut up about it. Re-authorizing now-banned school playground activities and school outings would help too. But it is so much easier to blame obesity on the evil "multinationals" than it is to blame it on your own restrictions on the natural activities of kids

12. Fascism: "What we should be doing is monitoring children from birth so we can detect any deviations from the norm at an early stage and action can be taken". Who said that? Joe Stalin? Adolf Hitler? Orwell's "Big Brother"? The Spanish Inquisition? Generalissimo Francisco Franco Bahamonde? None of those. It was Dr Colin Waine, chairman of Britain's National Obesity Forum. What a fine fellow!

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Trans fats: For one summary of the weak science behind the "trans-fat" hysteria, see here. Trans fats have only a temporary effect on blood chemistry and the evidence of lasting harm from them is dubious. By taking extreme groups in trans fats intake, some weak association with coronary heart disease has at times been shown in some sub-populations but extreme group studies are inherently at risk of confounding with other factors and are intrinsically of little interest to the average person.

The "antioxidant" religion: The experimental evidence is that antioxidants SHORTEN your life, if anything. Studies here and here and here and here and here and here and here and here, for instance. That they are of benefit is a great theory but it is one that has been coshed by reality plenty of times.

The medical consensus is often wrong. The best known wrongheaded medical orthodoxy is that stomach ulcers could not be caused by bacteria because the stomach is so acidic. Disproof of that view first appeared in 1875 (Yes. 1875) but the falsity of the view was not widely recognized until 1990. Only heroic efforts finally overturned the consensus and led to a cure for stomach ulcers. See
here and here and here.

Dieticians are just modern-day witch-doctors. There is no undergirding in double-blind studies for their usual recommendations

The fragility of current medical wisdom: Would you believe that even Old Testament wisdom can sometimes trump medical wisdom? Note this quote: "Spiess discussed Swedish research on cardiac patients that compared Jehovah's Witnesses who refused blood transfusions to patients with similar disease progression during open-heart surgery. The research found those who refused transfusions had noticeably better survival rates.

Medical wisdom can in fact fly in the face of the known facts. How often do we hear reverent praise for the Mediterranean diet? Yet both Australians and Japanese live longer than Greeks and Italians, despite having very different diets. The traditional Australian diet is in fact about as opposite to the Mediterranean diet as you can get. The reverence for the Mediterranean diet can only be understood therefore as some sort of Anglo-Saxon cultural cringe. It is quite brainless. Why are not the Australian and Japanese diets extolled if health is the matter at issue?

Since many of my posts here make severe criticisms of medical research, I should perhaps point out that I am also a severe critic of much research in my own field of psychology. See here and here

This is NOT an "alternative medicine" site. Perhaps the only (weak) excuse for the poorly substantiated claims that often appear in the medical literature is the even poorer level of substantiation offered in the "alternative" literature.

I used to teach social statistics in a major Australian university and I find medical statistics pretty obfuscatory. They seem uniformly designed to make mountains out of molehills. Many times in the academic literature I have excoriated my colleagues in psychology and sociology for going ga-ga over very weak correlations but what I find in the medical literature makes the findings in the social sciences look positively muscular. In fact, medical findings are almost never reported as correlations -- because to do so would exhibit how laughably trivial they generally are. If (say) 3 individuals in a thousand in a control group had some sort of an adverse outcome versus 4 out of a thousand in a group undergoing some treatment, the difference will be published in the medical literature with great excitement and intimations of its importance. In fact, of course, such small differences are almost certainly random noise and are in any rational calculus unimportant. And statistical significance is little help in determining the importance of a finding. Statistical significance simply tells you that the result was unlikely to be an effect of small sample size. But a statistically significant difference could have been due to any number of other randomly-present factors.

"The modern literature on hate crimes began with a remarkable 1933 book by Arthur Raper titled The Tragedy of Lynching. Raper assembled data on the number of lynchings each year in the South and on the price of an acre's yield of cotton. He calculated the correlation coefficient between the two series at -0.532. In other words, when the economy was doing well, the number of lynchings was lower.... In 2001, Donald Green, Laurence McFalls, and Jennifer Smith published a paper that demolished the alleged connection between economic conditions and lynchings in Raper's data. Raper had the misfortune of stopping his analysis in 1929. After the Great Depression hit, the price of cotton plummeted and economic conditions deteriorated, yet lynchings continued to fall. The correlation disappeared altogether when more years of data were added."

So we must be sure to base our conclusions on ALL the data. But in medical research, data selectivity and the "overlooking" of discordant research findings is epidemic.

The Truth About Ancel Keys. Keys was a brilliant man but his concentration on heart disease misled him. He was right that high fat intake predicted high rates of heart disease (though it was ANIMAL fat in particular that was the "culprit") but he overlooked that the same intake predicted LESS mortality from other causes. The same narrow vision led him to be the earliest prominent advocate of the "Mediterranean diet" hypothesis. It's true that Mediterraneans have less heart disease but they have more of other causes of death, so that Mediterranean countries do not have particularly long lifespans when compared with other developed countries. If there are any lessons about diet to be learned from lifespans, it is un-Mediterranean countries like Australia and the Nordic countries that one should look to.

The intellectual Roman Emperor Marcus Aurelius (AD 121-180) could have been speaking of the prevailing health "wisdom" of today when he said: "The object in life is not to be on the side of the majority, but to escape finding oneself in the ranks of the insane."

Improbable events do happen at random -- as mathematician John Brignell notes rather tartly: "Consider, instead, my experiences in the village pub swindle. It is based on the weekly bonus ball in the National Lottery. It so happens that my birth date is 13, so that is the number I always choose. With a few occasional absences abroad I have paid my pound every week for a year and a half, but have never won. Some of my neighbours win frequently; one in three consecutive weeks. Furthermore, I always put in a pound for my wife for her birth date, which is 11. She has never won either. The probability of neither of these numbers coming up in that period is less than 5%, which for an epidemiologist is significant enough to publish a paper.

Kids are not shy anymore. They are "autistic". Autism is a real problem but the rise in its incidence seems likely to be the product of overdiagnosis -- the now common tendency to medicalize almost all problems.

One of the great pleasures in life is the first mouthful of cold beer on a hot day -- and the food Puritans can stick that wherever they like

NOTE: The archives provided by blogspot below are rather inconvenient. They break each month up into small bits. If you want to scan whole months at a time, the backup archives will suit better. See here or here